Blood Vessel - S1-E2
Trivia: The secretive room on the ship with a dark secret is cabin no. 9. Mark Gatiss, co-writer of this series, also co-wrote another creepy BBC series called "Inside No. 9"
Et in Arcadia Ego: Part 2 - S1-E10
Trivia: The ships that Riker arrives with are all identical, explained away with the line "I've got a fleet of them at my back." That line's delivered without seeing Riker's face, because it was recorded afterwards. The effects work was only completed shortly before the episode was released, and they didn't have time to create a variety of ships, leading to this "shortcut."
Trivia: One of their firefighters is shot and out of work. When the team was saying how long he would be out, Judd Ryder is telling his coworkers about a firefighter in Los Angeles Howie "Chimney" Han who had a rebar stuck in his brain and came back to work within a month. This is an homage/crossover to the original series 9-1-1 where this actually happened to Howie Han in one of the episodes. (00:00:10)
Trivia: The character of Dani Clayton is named after Jack Clayton, who directed "The Innocents." "The Innocents" is the film adaptation of the stage version of Henry James' "The Turn of the Screw." (Source: ScreenRant).